This invention concerns a round baler with at least one traction means to move crop for baling or to or in a baling chamber and with rolls over which the traction means runs and more specifically concerns a tracking control for such traction means.
Round balers are used to take up crop to be baled and to wrap it on itself. Such round balers are frequently used in agriculture to collect straw or hay that is deposited in windrows on the ground. The outer shape of the bale depends upon the uniformity of supply of the crop to be baled. If the supply of the crop to be baled is not uniform, the traction means is loaded on one side, which sets the bale into rotation, so that in addition to the component of movement in the direction of operation of the traction means, a component perpendicular thereto is developed that permits the traction means to run at a slant. This slant running can lead to tearing of the traction means or, if several traction means are running in parallel on the roll, they may cross over one another.
It is known from U.S. Pat. No. 4,224,867, that the shape of a round bale can be monitored by sensors that detect the tension of the traction means configured as belts and provide the corresponding information to an operator as the distortion of the round bale by means of an optical or acoustic indicator. By modifying the loading, for example, the direction of driving, the operator can supply more crop to the side of the baler that is deficient in crop. However, following the signals of such sensors is not entirely satisfactory since it requires the constant attention of the operator.
In addition, it is known practice when using a multiplicity of belts alongside each other to provide guide vanes between the belts, which at the least prevent crossover between adjacent belts. However, the use of guide vanes is also not entirely satisfactory since it may lead to damage to the edges of the belts.